updating military strike options for president obama in the event he orders action. a senior u.s. official tells cnn a strike could be carried out with the ships and aircraft already stationed in the region. the planning is being driven by the latest intelligence which u.s. officials say shows sarin gas has been loaded into aerial bombs in at least two locations near airfields. syria seems to have crossed the line drawn by the president last august. >> a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. >> reporter: this week that line seems to have shifted with warnings from the president, secretary of defense panetta, and others focusing on what happens if assad uses the weapons. >> see, these lines become sort of pink lines. you know, they're not drawn with, you know, a fine pencil. and they move around a little. >> reporter: military options for striking syria spell out the case for why an attack might be called for. u.s. officials say there are multiple reports, more than just satellite imagery, confirming the